The morphology and tissue culture core will provide histological and tissue culture support for all three projects. Immunohistochemistry for tyrosine hydroxylase will be used as a primary marker for dopaminergic neurons. Quantitation of dopamine neuron numbers in grafted tissue and in the substantia nigra of MPTP treated monkeys will be assessed for each relevant experiment. Computer assisted three-dimensional reconstructions will be made, particularly for attempts at circuit reconstruction using striatal- nigral co-grafts. Additional morphological methods and techniques provided by this core and its personnel are cryopreservation, fluorescence histochemistry, riboprobe in situ hybridization for tyrosine hydroxylase, immunochemistry for a number of other transmitters. Core personnel perform all fetal brain dissections and participate in adult brain dissections and micropunches that rely upon a combined histochemical/biochemical procedure. The tissue culture facility will carry out pharmacologic studies described in Project 1.